sump flow question

[arctictwist]

i have a question about flow in and out of the sump. Say your overflow is rated at 300gph and your return pump is rated at 310 gph at the height youd be pumping back up, wont the sump eventually have too little water in it? how do you control that?

[kau_cinta_ku]

ball valve on the output of the return pump.

[howdy777]

if your return is too fast (to your tank), it will overflow your tank.. if the overflow can't keep up.. a ball valve is a good way to get around that, just make sure the valve is after the return going into your tank, you won't need much if anything.. did you factor in the pressure required to pump back up to your tank? may not need it at all..

[arctictwist]

i actually dont have a sump, it was just a thought i had while thinking about the process of it all. But i figured mine is 4 ft high, and the pump i looked at is rated at 310 ft with that height, and then i looked at overflows recommended for my 30 and they flowed 300 gph.